Not surprised. Their spotty Russian roulette styled QC is legendary at this point. You're lucky if that's your only QC issue, try checking if the front of the dome is aligned correctly.
Well as the store never sent a replacement figure.... I opened it and: the dome had several small cracks on the dome after what looks like some tool they used to put the dome attached to the head while the glue dries, and it had small openings between the dome and the head, never attached properly either. the front looked alright, no issues there.
The rest of the body was alright, just the head they f**ked up.
Got myself a new one, no wonder how neca make their money..... and this one is 98% perfect, no gabs between the dome and the head, nicely attached, one small mark from the tool at one place on the head but most people will miss it and I can accept that, the body is perfect. Although I ntoiced this one seem to be in a more soft plastic and less stiff and better allround details. Maybe neca started using a new plastic for their figures or improvment along the line.
Ahh well, at least I have now a perfect alien 40th anniversiary figure with correct white/smooky dome.